Howard: Sheldon, some day, if you get a car, I'm sure they'll give you another parking space.
Sheldon: I don't want another parking space. I want my parking space. It's perfect. It's a corner spot, cutting the risk of door-dings in half. It's a mere 28 steps from the building entrance. The nearby tree provides shade on hot days and is also home to a delightful squirrel. Which is fortuitous because most squirrels are real jerks.

Leonard: What are you doing?
Wolowitz: Well, he wasn't using it, and I needed some cool leather to wiggle my naked ass on.

Amy: Well, at least when we do make love, Sheldon won't be thinking about his mother. And yes, that is a cleverly veiled reference to Howard's lifelong obsession to crawl back into her spacious womb.

Leonard: All right, you brought this on yourself. Sheldon, get him.
Sheldon: If a zombie bites you, you turn into a zombie. However, if a mummy bites you, all you turn into is some schmo with a mummy bite. So, like a zombie that's been eaten from the waist down, you, sir, have no leg to stand on.

Leonard: Howard did go to the International Space Station.
Sheldon: Yeah, that was five weeks ago. How much longer is he gonna milk that cow?

Sheldon: Payback, it truly is the B word, isn't it?

Howard: Fine, I'm taking your diploma.
Sheldon: Go ahead. That's the only doctorate you'll ever get.

Amy: I guess this is what we get for being with two testosterone-fueled alpha males. At some point, they're bound to lock horns.
Penny: I'm assuming these are some kind of horns they bought at Comic-Con?

Sheldon: Give me back my parking space.
Howard: You don't need a parking space. You don't have a car.
Sheldon: You don't need an Iron Man helmet. You're not Iron Man.

Howard: Well, we appear to have reached an impasse. And you know, I have to say, I thought you'd be more upset that your laptop is sitting on my junk.

Sheldon: Keep a lookout. This place is swarming with campus security. They will not hesitate to scold us.
Amy: Freaking pigs.

Bernadette: More coffee?
Penny: No, Leonard's taking me to a physics lecture, and coffee'll just keep me awake.

Penny: Get away from me or I swear to God I will rip out what's left of your pubes!

Bernadette: The tow truck didn't scratch your car.
Amy: How do you know?
Bernadette: 'cause I did it!

Howard: He can't handle the fact that I'm a bigger deal than he is now.
Sheldon: Oh, preposterous. I have been solely responsible for this university's six loop quantum gravity calculations, I have changed the way we think about Bose-Einsten condensates, and I am also the one who got Nutter Butters in the cafeteria vending machine. Maybe you missed that news while you were floating around like a goof in outer space.